PYTHON将列表存储为csv文件以及从csv中提取数据2

Posted 2021-03-03 落月_YU

这回咱们用个pandas库

1.首先先看将列表存储到csv：

 代码来自于：https://blog.csdn.net/weixin_43245453/article/details/90054820

import pandas as pd
#a和b的长度必须保持一致，否则报错
a = [x for x in range(5)]
print(a)
b = [x for x in range(5,10)]
#字典中的key值即为csv中列名
dataframe = pd.DataFrame({\'a_name\':a,\'b_name\':b})
print(dataframe)

#将DataFrame存储为csv,index表示是否显示行名，default=True
dataframe.to_csv(r"test.csv",sep=\',\')

#结果：
[0, 1, 2, 3, 4]
   a_name  b_name
0       0       5
1       1       6
2       2       7
3       3       8
4       4       9

#text.csv
    a_name    b_name
0    0    5
1    1    6
2    2    7
3    3    8
4    4    9

比上回简单多了吧，真的的贫穷（知识储备）限制了我的想象！！！哈哈

 

 

 2.接着，我们开始读取：

import pandas as pd
from matplotlib import pyplot as plt

f = open(\'test.csv\',encoding = \'UTF-8\')

data=pd.read_csv(f) #将csv文件读入并转化为dataframe形式
print(data)
f1 = data[\'a_name\'].values
f2 = data[\'b_name\'].values

plt.rc(\'grid\',linestyle=\':\',color=\'green\')
plt.scatter(f1,f2,c=\'red\')
plt.grid()
plt.show()

   Unnamed: 0  a_name  b_name
0           0       0       5
1           1       1       6
2           2       2       7
3           3       3       8
4           4       4       9

 

 

 

 

3.出现以下问题请关闭csv文件：

Traceback (most recent call last):
  File "C:\\Users\\Administrator\\Desktop\\毕设\\程序\\导入数据\\小程序\\按列写入csv文件.py", line 11, in <module>
    dataframe.to_csv(r"test.csv",sep=\',\')
  File "C:\\Users\\Administrator\\AppData\\Local\\Programs\\Python\\Python37-32\\lib\\site-packages\\pandas\\core\\generic.py", line 3020, in to_csv
    formatter.save()
  File "C:\\Users\\Administrator\\AppData\\Local\\Programs\\Python\\Python37-32\\lib\\site-packages\\pandas\\io\\formats\\csvs.py", line 157, in save
    compression=self.compression)
  File "C:\\Users\\Administrator\\AppData\\Local\\Programs\\Python\\Python37-32\\lib\\site-packages\\pandas\\io\\common.py", line 424, in _get_handle
    f = open(path_or_buf, mode, encoding=encoding, newline="")
PermissionError: [Errno 13] Permission denied: \'test.csv\'